As U.S. forced reportedly prepare to launch a limited military action against the Syrian government, we turn now to a voice who's long made the case that the U.S. must take some action in Syria. Michael Ignatieff is a leading voice for the idea of humanitarian intervention. He helped develop the concept of the responsibility to protect. He is the former leader of Canada's Liberal party and now back on the faculty of the Carr Center for Human Rights Policy at Harvard's Kennedy School.

He joins us from Toronto. Mr. Ignatieff, thank so much for being with us.

MICHAEL IGNATIEFF: Thank you, Scott.

SIMON: What's your opinion of the proposed U.S. military action?

IGNATIEFF: Well, the President is saying that he wants a fire a shot across the bow Assad to demonstrate that no one can cross that line about using chemical weapons with impunity and I think a lot of Americans, a lot of Canadians support that idea, but I think that the troubling issue is that suppose he starts those strikes and we do, you know, 48 hours of them or something as a shot across the bow. On Tuesday or Wednesday of next week, civilians in Syria will still be dying, so my sense is that while we can't stop that killing in Syria as it goes on, it would be a very good idea if you're going to use these strikes to at least degrade the capacities so his capacity to do it again is significantly reduced.

So it really is a question of what the President decides this weekend and my sense is a shot across the bow is kind of what are you doing it for, but if you degrade the capacity so that at least we don't have more of these appalling crimes of war that left, you know, more than 1,000 people dead, that at least, I think, constitutes some justification for what he's trying to do. But he's got a line to walk because he's not in the business of regime change.

He's not in the business of an invasion, he's not in the business of even changing the military balance. But I think at least he has to degrade the capacity to use chemical weapons on a permanent basis.

SIMON: Mr. Ignatieff, are you suggesting that the U.S. government should be in the business of regime change or at least changing this regime?

IGNATIEFF: No, I mean, my view is that the time for that, if it ever arose, is long past. I've always believe that sooner or later this has to end with some kind of political settlement and I don't think regime change is a practical option here. But, you know, 100,000 people have died. It's destabilizing an entire region. It's risking the security of people all around us and, you know, I was thinking as I was about to come on, I was listening to the previous item with heartbreaking interview with a father who lost his son in 2006.

You can't listen to that without understanding how deeply reluctant Americans now are about the use of force and I think it's a terrible thing to say in a way, but that sacrifice should make us all cautions about the use of military power. I really agree with that, but we don't want a world in which tyrants can kill innocent women and children with chemical weapons.

That has be stopped. And then the question is how do we stop it so it doesn't start again. That's, I think, where we are and that's, I think, where we should stay in terms of the use of force.

SIMON: We don't have a lot of time let, Mr. Ignatieff, although you've been very well spoken. What would you say to people who have asked this week, who have sited the 100,000 Syrians who have died, as you have, and said look, that's terrible but really what's different now that calls on the U.S. or anyone to get involved?

IGNATIEFF: Well, these are good arguments and as I say, once the military operations in Syria end, they will still be dying. But I do think chemical weapons are in a particular zone of horror because of their absolutely indiscriminate character. The minute you release chemical weapons, children, women, non-combatants are going to die. That's the purpose of using them. And, you know, Saddam Hussein did use them in Halabja, Northern Iraq, seen what that looks like when you use chemical weapons.

It's just awful. It was awful last week, and in that sense the particular awfulness of that weapon.